This final segment is devoted to the use of plastic coatings. The advent of epoxy compounds for commercial construction has brought about a radical change in the long established concepts of surface protection for exposed concrete. Epoxy compounds can be used as paint type protective coatings to provide both waterproof and vaporproof membranes, as epoxy mortars for floor toppings to be installed in places where concrete slabs have badly deteriorated, and as skid-resistant coating of both the film and mortar types. The biggest advantage of the epoxy coatings for floor protection is the fact that a good epoxy coating is highly resistant to chemicals. This means that it can be used to protect concrete in area such as dairy barns, food packing plants, aircraft hangars and machine shops where excessive spillage of fluids occurs. All these are areas where the epoxy protective coatings are particularly well suited. One of the most satisfactory ways to apply an epoxy mortar topping to concrete floors is to first install one-fourth of an inch high aluminum strips such as are used for terrazzo. These strips are bonded to the concrete slab by means of the gel type epoxy adhesives. After mixing, the epoxy resin mortar is spread in alternate squares formed by the aluminum strips and then compacted by using a large aluminum pipe roll. This roller should ride upon the aluminum strips which then act as screeds. Two or three passes of the roller will thoroughly compact the mortar in the square with the added advantage that it does not pick up the somewhat sticky mortar.